A circulating, submerged organ culture system was used to study the effects of physical modifications of the craniofacial area on elevation of the secondary palate. It was found that the tongue must be removed and the region of the oral cavity posterior to the base of the tongue must be intact for palatal elevation to take place. In the coming year we will continue in vitro studies of palatal elevation. Studies will utilize both physical and chemical manipulations of the palatal shelves, other craniofacial structures and the culture medium. Experiments using substances and culture conditions known to inhibit or stimulate contractility at various levels will also be performed. BIBLIOGRAPHIC REFERENCES: Brinkley, L., Basehoar, J., Branch, A. and Avery, J. (1975) A new in vitro system for studying secondary palate development. J. Embryol. exp. Morph. 34, 485-495. Brinkley, L. and Avery, J. (1975) Mechanical intervention with the cranial base during palatal shelf elevation in vitro. J. Dent. Res, 54, 80 (Abstract).